Broadcasting is a process of distribution of audio and/or video to dispersed audience through various electronic mass communication mediums. In recent days, digital radio broadcasting has become more popular because of its audio quality compared to traditional analog radio broadcasting. The digital radio broadcasting exists in frequency bands such as used by AM, FM bands and also in other bands for data transmission and reception. It may include several channels that contain audio, informational data, diagnostic parameters and other data.
Digital Radio Mondiale (DRM) is a broadcasting standard at AM bands below 30 MHz and VHF bands above 30 MHz. It is a high quality digital replacement for analogue radio broadcasts of AM and FM frequency. The DRM digital radio stream contains three channels namely a Main Service Channel (MSC), a Fast Access Channel (FAC), and a Service Description Channel (SDC). The MSC may contain an audio or informational data, depending on the type of service being broadcast. The FAC may contain transmission frame id, type of modulation of SDC & MSC, number of services, type of services and part information on how to decode MSC. The SDC may contain information about the received DRM digital radio stream, such as a radio station identifier, geographic location, time, date, and other information including additional information to decode MSC.
DRM has the following features,                i. Supports both audio and data output;        ii. Provides good audio quality;        iii. Provides more number of services in a single frequency;        iv. Supports simulcasts (transmission of analog and digital simultaneously);        v. Supports data services like Journaline, Electronic Programme Guide (EPG) and Slide show; and        vi. Supports Emergency Warning System (EWS) and Alternate Frequency Switching (AFS).        
Further, DRM has different robustness modes used under different propagation conditions. Robustness Modes A, B, C and D are used for transmissions under 30 MHz and Robustness Mode E is used in VHF bands. Modulation parameters are different for different Robustness Modes.
One of the major performance differentiator of DRM Receivers is the acquisition time taken by the receiver. Acquisition time is the time taken by the receiver to output the audio signal after receiving the DRM radio signal i.e. after tuning to a frequency. The radio data stream (both audio and data) is contained in the MSC. To start MSC processing, receiver needs SDC channel information. Based on first received transmission frame, acquisition time will change. Following are the three conditions on reception of the transmission frames.                i. First received transmission frame is Frame-0 and SDC is absent: As per DRM transmission frame structure, SDC is part of Frame-0. MSC processing will start after the reception of SDC. After getting SDC, to provide audio data for decoding, receiver will take 800 ms delay for short interleaver depth and 2400 ms delay for long interleaver depth. If the SDC is not obtained from the first frame itself, DRM receiver has to wait for SDC. This time is 1146.68 ms in the case of robustness mode A and B (2 SDC symbols and duration of one symbol is 26.66 ms). For robustness mode C, the wait time is 1140 (3 SDC symbols and duration of one symbol is 20 ms). For robustness mode D, the wait time is 1150.02 (3 SDC symbols and duration of one symbol is 16.66 ms). Here, the MSC symbols received before SDC are lost and acquisition takes additional 1146.68 ms for robustness mode A and B, 1140 ms for robustness mode C and 1150.02 for robustness mode D to audio out after receiving first frame.        ii. First received transmission frame is Frame-1: FAC is obtained in the first frame. To get first SDC, receiver has to wait 800 ms. After receiving the SDC, receiver starts MSC processing. After getting SDC, to provide audio data for decoding, receiver will take 800 ms delay for short interleaver depth and 2400 ms delay for long interleaver depth. Here, the MSC symbols received before SDC are lost and acquisition takes additional 800 ms to audio out after receiving first frame.        iii. First Received transmission frame is Frame-2: FAC is obtained in the first frame. To get first SDC, receiver has to wait 400 ms. After receiving the SDC, receiver starts MSC processing. After getting SDC, to provide audio data for decoding, receiver will take 800 ms delay for short interleaver depth and 2400 ms delay for long interleaver depth. Here, the MSC symbols received before SDC are lost and acquisition takes additional 400 ms to audio out after receiving first frame.        
Conventionally, many systems and methods are known in the existing art that have been proposed to overcome the problems associated with the time taken to execute the data frames at the receiver end.
Japanese Patent Application No. 2007088923 to Alpine Electronics Inc, entitled “Receiver and reception frequency detecting method” deals with a receiver and reception frequency detection method to search receivable frequencies in a short period of time in Digital Radio Mondiale system. A broadcast schedule creation unit creates a broadcast schedule list based on the detected schedule information and stores schedule list in the memory and during seek operation the reception frequency is searched in the list thereby eliminating the need of searching unnecessary frequencies.
However, the above solution does not overcome the delay caused during the processing of frames. Hence, further developments have been proposed to avoid time delay in processing of frames using memory units.
U.S. Pat. No. 7,974,338 to Harman Becker Automotive Systems GmbH, entitled “System for decoding a digital radio stream” deals with a method for improving user experience in DRM by outputting data contained in Fast Access Channel (FAC) and Service Description channel (SDC) without waiting for the Main Service Channel (MSC) decoding to finish. The DRM channels (FAC, SDC, MSC) decoded data is stored in a memory and reused to improve acquisition time.
European Patent Document No. 1104138 to Robert Bosch Gmbh, entitled “Descrambling of data frames” discloses a method for reducing audio decoding delay in Digital Radio systems like Digital Radio Mondiale (DRM). By selecting the most likely frame configuration for a frequency and by filling the memory of de-interleaver with demodulated data before the control channel is decoded; parallel processing of information has been performed and thereby delay time is reduced in the receiver side.
Though the above existing systems and methods disclose storing of decoded DRM signal data in memory unit for reducing delay in Digital Radio Mondiale (DRM) receiver, still there exists time delay for reception and processing of frames during frame execution or during incorrect selection of configuration
To overcome these problems and thereby to improve user experience, the present invention proposes a system and method to improve the acquisition time by storing the demodulated data on memory unit. After identifying the first frame id by decoding FAC, the stored demodulated data from memory is re-split to get MSC channel data. This MSC data is stored in memory unit and once SDC is available, MSC data stored in memory unit is decoded.